Save the Earth in Two Not-So-Hard Questions

What Steven Landsburg doesn't understand about climate change.

In response to the recent announcement of the Nobel Peace Prize, Slate economist Steven Landsburg has written an ill-informed hit piece on Al Gore. "Save the Earth in Six Hard Questions: What Al Gore doesn't understand about climate change" argues that "there's nothing particularly peaceable about Gore's rhetorical approach," and that anyone who doesn't talk about climate change in purely economic terms is full of hot air. In fact, Gore understands what Landsburg doesn't: The realities of catastrophic global warming can render economic analysis largely moot.

Landsburg poses six questions to get at what he sees as the central issue—the trade-off between "the quality of our own lives and the quality of our descendants." Once you understand the reality of climate science and climate solutions, however, the supposed trade-off disappears. We really need to answer just two questions:

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1. How great a threat does inaction on climate change pose for future generations' quality of life—and for life itself?

Answering this question was perhaps the central goal of Gore's movie, AnInconvenient Truth. In short, climate change is the gravest of threats—a point economists like Landsburg seem to miss. Truly catastrophic outcomes remain a distinct possibility: Sea levels were 25 meters higher about 3 million years ago, when global temperatures were 2 degrees to 3 degrees Celsius warmer than they are today—a warming we will see this century under business-as-usual emissions trends. And the oceans could rise a meter every 20 years for centuries to come, as NASA's James Hansen has explained. A few economists, like Harvard's Martin Weitzman, have shown that these plausible worst-case scenarios will dominate any serious economic analysis of climate change.

Landsburg claims, "Climatologists estimate what it takes to put New York underwater; economists estimate the cost of moving New York inland." No. Few, if any, economists would bother to estimate thecost of moving New York City, with its unique physical assets and vast infrastructure—let alone the billion people worldwide who would lose their homes if sea levels rose 25 meters. Economists do estimate the cost of building levees, but how do we build levees if sea levels are rising more than a foot a decade—and if many coastal cities face Katrina-like superstorms in the future?

Next, Landsburg asserts that "if the world temperature rises 3 degrees, agronomists try to predict the wheat yield in Oklahoma; economists try to predict when Oklahomans will turn to alternate ventures—and when it will become profitable to grow wheat in Alaska." Suppose Oklahoma's climate changes and it enters a permanent drought, as some studies suggest—along with the entire Southwest and many parts of the world. What "alternate ventures" will thrive in a permanent Dust Bowl? Suppose the climate passes a tipping point whereby carbon sinks like the ocean saturate (as they are beginning to now) and carbon sources like the tundra start to churn out their own emissions—and the climate never stabilizes enough to allow wheat to be grown in Alaska?

Landsburg thinks climate problems are very, very distant. So he keeps posing the wrong questions:

Just how rich are those future generations likely to be?If you expect economic growth to continue at the average annual rate of 2.3 percent, to which we've grown accustomed, then in 400 years, the average American will have an income of more than $1 million per day—and that's in the equivalent of today's dollars (i.e., after correcting for inflation). Does it really make sense for you and me to sacrifice for the benefit of those future gazillionaires?

Seriously, in 400 years we'll all be Bill Gates, so let's party now! In fact, the Southwest faces a permanent drought from global warming by 2050. Scientists fear the sea-level rise could exceed one meter by century's end—but more importantly, a far greater rise will be unstoppable if we don't act quickly.

Landsburg also asks: "How likely are those future generations to be around, anyway? If you think life on Earth will be destroyed by an asteroid in 200 years, it makes little sense to worry about the climate 300 years from now."

No wonder it is said that economists understand the price of everything but the value of nothing. If you really think life on Earth will be destroyed by an asteroid in 200 years, then the answer is not to blindly accept our own extinction and at the same time ignore climate change mitigation. The answer is to spend the money today needed to mitigate the chance of the asteroid collision (and of catastrophic global warming).

Now we know what truly meaningful "quality of life" losses future generations may face: Irreversible destruction of our coasts, hundreds of millions of environmental refugees, whole regions of the planet in permanent or near-constant drought, and massive species extinction on land and sea, to name but a few. (And these impacts are the genuine threat to world peace that Al Gore has sought to warn people about, which justifies his Nobel Prize.)

Which brings us to the second question:

2. Will significant action on climate change require sacrificing our quality of life in any meaningful sense?

You don't need to be an economist to realize the answer is a definite no. I ran the Office of Energy Efficiency and Renewable Energy under Clinton-Gore, and our research showed that action on climate change does mean we will have to spend a lot of money on carbon-free energy sources—but we will also save a lot of money over the long term. Consider that in terms of electricity consumption, the average Californian generates less than one-third the carbon dioxide emissions of the average American while paying the same annual bill.This has not required sacrifice, just intelligent regulations that encourage energy efficiency and clean energy.

According to a major PricewaterhouseCoopers study (PDF), we can reduce carbon emissions by around 60 percent by 2050, with a total reduction in GDP of just 2 percent to 3 percent. So, either we sacrifice one year of economic growth over the next four decades, or else the next 50 generations will have to sacrifice a livable climate. And this is very similar to the Stern Review's conclusion that Landsburg endorses in his final paragraph. Not a very tough choice—even for noneconomists.

Landsburg seems to believe that only economists can discuss climate change seriously, while the rest of us are wasting everyone's time: "If you're not talking about discount rates and levels of risk aversion, you're blathering." Landsburg's piece proves that you can talk about those things and still be blathering.

Steven E. Landsburg responds:

Nothing that Joe Romm (or Al Gore) can tell us about the dire effects of global warming can tell us how much we ought to spend to combat it. Should we spend 1 percent of our incomes? Five percent? Twenty percent? "A whole lot" is not a useful answer to that question.

Because future generations are among the beneficiaries of climate control, the appropriate expenditure level depends critically on the questions Mr. Romm would prefer to ignore: How much do we care about those future generations? How likely are they to be around in the first place? And how rich are they likely to be?

Those are hard questions. But a refusal to confront them is a refusal to take climate issues seriously. I think climate policy is important enough to think about. Mr. Romm, apparently, prefers to bury his head in the sand.